SkPDF: Subset Type3 (fallback) font

src/pdf/SkPDFDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPDFDevice.h"
 #include "SkAnnotationKeys.h"
 #include "SkBitmapDevice.h"
@@ skipping 1188 matching lines @@
     content.entry()->fContent.writeText("BT\n");
     set_text_transform(x, y, textPaint.getTextSkewX(),
                        &content.entry()->fContent);
     int consumedGlyphCount = 0;
 
     SkTDArray<uint16_t> glyphIDsCopy(glyphIDs, numGlyphs);
 
     SkPDFGlyphSetMap* fontGlyphUsage = fDocument->getGlyphUsage();
 
     while (numGlyphs > consumedGlyphCount) {
-        this->updateFont(textPaint, glyphIDs[consumedGlyphCount], content.entry());
+        if (!this->updateFont(textPaint, glyphIDs[consumedGlyphCount], content.entry())) {
+            SkDebugf("SkPDF: Font error.");
+            content.entry()->fContent.writeText("ET\n%SkPDF: Font error.\n");
+            return;
+        }
         SkPDFFont* font = content.entry()->fState.fFont;
 
         int availableGlyphs = font->glyphsToPDFFontEncoding(
                 glyphIDsCopy.begin() + consumedGlyphCount,
                 numGlyphs - consumedGlyphCount);
         fontGlyphUsage->noteGlyphUsage(
                 font,  glyphIDsCopy.begin() + consumedGlyphCount,
                 availableGlyphs);
         write_wide_string(&content.entry()->fContent,
                           glyphIDsCopy.begin() + consumedGlyphCount,
@@ skipping 46 matching lines @@
         return;
     }
 
     SkGlyphStorage storage(0);
     const uint16_t* glyphIDs = nullptr;
     size_t numGlyphs = force_glyph_encoding(paint, text, len, &storage, &glyphIDs);
     textPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
     SkAutoGlyphCache autoGlyphCache(textPaint, nullptr, nullptr);
 
     content.entry()->fContent.writeText("BT\n");
-    this->updateFont(textPaint, glyphIDs[0], content.entry());
+    if (!this->updateFont(textPaint, glyphIDs[0], content.entry())) {
+        SkDebugf("SkPDF: Font error.");
+        content.entry()->fContent.writeText("ET\n%SkPDF: Font error.\n");
+        return;
+    }
     GlyphPositioner glyphPositioner(&content.entry()->fContent,
                                     textPaint.getTextSkewX(),
                                     content.entry()->fState.fFont->multiByteGlyphs());
     SkPDFGlyphSetMap* fontGlyphUsage = fDocument->getGlyphUsage();
     for (size_t i = 0; i < numGlyphs; i++) {
         SkPDFFont* font = content.entry()->fState.fFont;
         uint16_t encodedValue = glyphIDs[i];
         SkScalar advanceWidth = autoGlyphCache->getGlyphIDAdvance(encodedValue).fAdvanceX;
         if (font->glyphsToPDFFontEncoding(&encodedValue, 1) != 1) {
             // The current pdf font cannot encode the current glyph.
             // Try to get a pdf font which can encode the current glyph.
             glyphPositioner.flush();
-            this->updateFont(textPaint, glyphIDs[i], content.entry());
+            if (!this->updateFont(textPaint, glyphIDs[i], content.entry())) {
+                SkDebugf("SkPDF: Font error.");
+                content.entry()->fContent.writeText("ET\n%SkPDF: Font error.\n");
+                return;
+            }
             font = content.entry()->fState.fFont;
             glyphPositioner.setWideChars(font->multiByteGlyphs());
             if (font->glyphsToPDFFontEncoding(&encodedValue, 1) != 1) {
                 SkDEBUGFAIL("PDF could not encode glyph.");
                 continue;
             }
         }
         fontGlyphUsage->noteGlyphUsage(font, &encodedValue, 1);
         SkScalar x = offset.x() + pos[i * scalarsPerPos];
         SkScalar y = offset.y() + (2 == scalarsPerPos ? pos[i * scalarsPerPos + 1] : 0);
@@ skipping 690 matching lines @@
     // Assumes that xobject has been canonicalized (so we can directly compare
     // pointers).
     int result = fXObjectResources.find(xObject);
     if (result < 0) {
         result = fXObjectResources.count();
         fXObjectResources.push(SkRef(xObject));
     }
     return result;
 }
 
-void SkPDFDevice::updateFont(const SkPaint& paint, uint16_t glyphID,
+bool SkPDFDevice::updateFont(const SkPaint& paint, uint16_t glyphID,
                              SkPDFDevice::ContentEntry* contentEntry) {
     SkTypeface* typeface = paint.getTypeface();
     if (contentEntry->fState.fFont == nullptr ||
             contentEntry->fState.fTextSize != paint.getTextSize() ||
             !contentEntry->fState.fFont->hasGlyph(glyphID)) {
         int fontIndex = getFontResourceIndex(typeface, glyphID);
+        if (fontIndex < 0) {
+            return false;
+        }
         contentEntry->fContent.writeText("/");
         contentEntry->fContent.writeText(SkPDFResourceDict::getResourceName(
                 SkPDFResourceDict::kFont_ResourceType,
                 fontIndex).c_str());
         contentEntry->fContent.writeText(" ");
         SkPDFUtils::AppendScalar(paint.getTextSize(), &contentEntry->fContent);
         contentEntry->fContent.writeText(" Tf\n");
         contentEntry->fState.fFont = fFontResources[fontIndex];
     }
+    return true;
 }
 
 int SkPDFDevice::getFontResourceIndex(SkTypeface* typeface, uint16_t glyphID) {
     sk_sp<SkPDFFont> newFont(
             SkPDFFont::GetFontResource(fDocument->canon(), typeface, glyphID));
+    if (!newFont) {
+        return -1;
+    }
     int resourceIndex = fFontResources.find(newFont.get());
     if (resourceIndex < 0) {
         resourceIndex = fFontResources.count();
         fFontResources.push(newFont.get());
         newFont.get()->ref();
     }
     return resourceIndex;
 }
 
 static SkSize rect_to_size(const SkRect& r) {
@@ skipping 201 matching lines @@
 }
 
 sk_sp<SkSpecialImage> SkPDFDevice::makeSpecial(const SkImage* image) {
     return SkSpecialImage::MakeFromImage(SkIRect::MakeWH(image->width(), image->height()),
                                          image->makeNonTextureImage());
 }
 
 sk_sp<SkSpecialImage> SkPDFDevice::snapSpecial() {
     return nullptr;
 }